PETER: Where are all the guns? That's what I want to know.
PAUL: Oh, you don't get a gun for a long while yet.
PETER: Well, if I'm gonna bump off the enemy, I gotta have some practice.
MUELLER: Bayonet drill. That's what I want.
ALBERT: You won a medal that time, Mueller.
MUELLER: You wait. In about a month, I'll be covered with them.
When Paul and his friends first join the army, they treat the upcoming war like boys playing war. Death seems to have no consequences other than being tagged out of the game, and as the heroes of the story, they believe they'll be sporting a shiny coat of plot armor.
KEMMERICK: He's dead. He's dead.
KAT: Why did you risk your life bringing him in?
KEMMERICK: But it's Behn. My friend.
KAT: It's a corpse, no matter who it is.
But the game gets real when the 2nd Company has wiring duty at the Front. Paul and his friends suffer their first lost, and Kat has to teach them the harsh lesson of the Front: one man's corpse is not worth another man's life. In an adventure tale, Kemmerick's actions might be seen as heroic. In a real war, they're foolhardy.
PAUL: Muller. I saw him die. I didn't know what it was like to die before. And then…then I came outside and it felt…it felt so good to be alive that I started in to walk fast. I began to think of the strangest things, like being out in the fields. Things like that. You know, girls. And it felt as if there were something electric running from the ground up through me.
Death affects the soldiers differently. When Behn died, Kemmerick sank into a deep depression that resulted in psychological trauma. When Paul saw Kemmerick die, he was sad but also thankful that he was still alive.
[Mueller marches to the Front in Kemmerick's boots, but during an assault, he is killed. Peter inherits the boots, but in the next scene, Peter is hit and killed going over the top.]
Kemmerick's boots aren't cursed, but through them, we see the trail of death Paul's friends walk. The movie treats these deaths less ceremoniously than it did Behn's or Kemmerick's. Like the characters, the audience has begun to grow accustomed to seeing death.
PAUL: You'll have to forgive me, comrade. I'll do all I can. I'll write to your parents. I'll write to…
[Checks the soldier's papers.]
PAUL: I'll write to your wife. I'll write to her. I promise she'll not want for anything. And I'll help her and your parents, too. Only, forgive me. Forgive me! Forgive me. Forgive me. [Sobbing.] Forgive me…
Looking at the French soldier's papers, Paul learns his name is Duval and he has a family waiting for him at home. This realization leads Paul into a deep depression as he begs the man's corpse for forgiveness. The French soldier provides a name for the so-far nameless enemy, and Paul learns it is far easier to kill "the enemy" than it is to kill a person.
PAUL: Terrible thing happened yesterday. I stabbed a man. With my own hands, stabbed him.
KAT: I know how it is. Your first time. Never mind. The stretcher-bearers will find him.
PAUL: No, no. He's dead, Kat. I watched him die.
KAT: You couldn't do anything about it. We have to kill. We can't help it. That's what we are here for.
Although Paul's upset over the French soldier's death, he also realizes another truth about the war with Kat's help: you either kill or you're killed. If Paul hadn't stabbed the French soldier, likely it would have been him dying slowly and painfully in a crater in the middle of No Man's Land.
[Paul notices a butterfly just outside his shooter's nest. He reaches for it, and a French sniper notices him. Paul's hand slowly reaches for the butterfly. A shot cracks; Paul's hand jerks. Then it lies limp in the mud as Paul dies.]
In keeping with the reality of war, no one, not even our protagonist, is safe from death. Paul doesn't die after providing a grand, motivational speech or performing some heroic deed. He simply dies.